This invention relates to a process for the production of styrene by the dehydrogenation of ethylbenzene in the presence of steam and more particularly to a method of reducing the fouling of certain process components due to polymer formation.
In styrene manufacturing processes, many plants experience troublesome fouling and even plugging problems in certain equipment and particularly in the main condenser system, off-gas compressor and downstream cooler and lean oil scrubber/stripper system. This polymer formation is mainly due to the presence of uninhibited styrene and in many cases is aggravated by the presence of small concentrations of divinylbenzene and other polymer precursors produced along with styrene in the dehydrogenation reactor as a side reaction and also as a product of the dehydrogenation of diethylbenzene which may be present in the feed.
The invention relates to the reduction or elimination of the fouling in a styrene production process by removing polymerizable materials from the process stream upstream of the process components subject to fouling. More particularly, the invention relates to the scrubbing/prefractionation of the dehydrogenation effluent to remove divinylbenzene and styrene prior to the condensing of the effluent in the main condenser system with the scrubber/prefractionation being refluxed by organic condensate from the main condenser system. Alternately, the scrubber may include a reboiler and a stripping section and function as a full fractionator thereby reducing or eliminating the need for downstream distillation equipment and systems.